This invention relates to powered sliding door operating systems for vehicles and, more particularly, to powered sliding door operating systems for van type vehicles having a door opening in a side wall of the van, wherein the sliding door is moved generally parallel to the van side wall during its initial closing movement and for a major portion of its full closing movement, as well as during a major portion of its full opening movement, including its final opening movement, and wherein the sliding door moves generally toward and generally away from the plane of the door opening in its respective final closing and initial opening movements, so as to be flush with the side wall when fully closed and to be alongside of and parallel to the side wall, to the rear of the door opening, when fully opened.
In sliding door systems of the foregoing type, upper and lower forward guide rails ar attached to the top and bottom portions, respectively, of the door opening, and a rear guide rail is attached to the exterior of the side wall, at an elevation that is approximately midway between the elevation of the upper and lower forward guide rails. The respective forward end portions of the various guide rails are curved inwardly of the body of the van, and bracket and roller assemblies fastened to the respective upper and lower forward ends of the sliding door and to an intermediate position at the rear end of the sliding door are slidingly supported in the guide rails to guide the door through its opening and closing movements.
The various portions of the movements that sliding doors of vans undergo during opening and closing thereof have different power requirements Thus, the initial door closing movement and a major portion of the door closing movement that follows it is a high displacement/low force traversing movement, during which little force is required to achieve large movements of the door since only frictional resistance and grade-caused resistance, if any, must be overcome. Similarly, the final opening movement and a major portion of the opening movement which precedes it is a high displacement/low force traversing movement for the same reasons. On the other hand, the final closing movement of the door is a low displacement/high force motion, since at this time an elastomeric weather seal which surrounds the door opening must be compressed and, also, an unlatched latch bolt member carried at the rear end of the door must engage and be rotated to a latched position by a striker pin carried by the van body at the rear end of the door opening.
In manually operated sliding door units for van type vehicles the sliding door is typically moved with great momentum through its closing movement in order to insure that it will fully compress the weather seal strip at the end of such movement and, also, that the latch bolt member will be rotated to its latched position in engagement with the striker pin at such time. Such high momentum movement of the sliding door member presents a significant safety problem with respect to vehicle occupants, who may inadvertently have failed to remove portions of their body from the path of movement of the sliding door.
Various attempts have heretofore been made to mechanize or power the opening and closing movements of sliding doors of van type vehicles. One such attempt is illustrated in U.S. Pat. No. 4,612,729 to Sato. In the Sato patent a motor driven pinion carried by the lower front bracket and roller assembly of the door cooperates with a rack gear carried by the lower front guide rail in the door opening to move the door between its fully open and fully closed positions. In this arrangement, as in the case of the manually operated door discussed above, the rear of the door completes its closure due to a high momentum imparted to it during its closing movement and, therefore, the safety hazard discussed above is not overcome.
Similarly, U.S. Pat. Nos. 4,617,757 to Kagiyama et al and No. 4,640,050 to Yamagishi et al represent additional attempts to mechanize the opening and closing movements of van doors. They employ cable drives which are coupled to the lower front bracket and roller assemblies of the doors to move the doors through their opening and closing movements. Here, again, the systems rely on momentum to complete the door closing movements and, thus, do not satisfactorily meet the safety problems that attend such high momentum closing movements.
U.S Pat. No. 4,462,185 to Shibuki et al represents yet another patent relating to mechanizing the movement of van doors. In this case a friction wheel engages the bottom portion of the door and is employed to drive the door through the major portions of its opening and closing movements parallel to the side wall of the van. In addition a pair of turntable arms pivotably connected end-to-end between the friction wheel and the floor of the door opening is utilized to draw the rear of the door inward against the compression forces of the weather seal strip. While this prior art design presumably operates with lower momentum forces generated during the closing movement than those discussed above, it employs a complicated, costly mechanism which is difficult to originally install and difficult to repair in the event of a breakdown. Moreover, it would be difficult, at best, to retrofit the mechanism shown in this patent to a van type vehicle that was not originally designed to receive it.
In addition to the foregoing prior art attempts to mechanize or power the opening and closing movements of sliding doors of van type vehicles, final closing devices or clamping mechanisms for powering the final low displacement/high force movement of sliding van doors are in current development by the assignee of the present application. Two such low displacement/high force final closing or clamping mechanisms have been shown and described in the co-pending applications of James G. Boyko, Ser. No. 100,940, filed Sept. 25, 1987 and James G. Boyko et al, Ser. No. 119,824, filed Nov. 12, 1987, which applications are assigned to the assignee of the present application. The disclosures of the aforesaid two applications are incorporated by reference into the present application. In each of said co-pending applications a final closing device or clamping mechanism for the sliding door of a van type vehicle is disclosed. In each case the door includes a latch bolt member movable between latched and unlatched positions, and a handle or a lock member movable between open and closed positions. The final closing device or clamping mechanism in each case includes a striker support plate that is mounted on the vehicle body at the rear end of the opening for the sliding door for rotational movement about an axis perpendicular to such plate; a striker pin carried by the striker support plate and projecting therefrom at a position eccentrically offset from the axis; and, means carried by the vehicle body and connected to the striker support plate for rotating the striker support plate. The striker pin is movable between an extended and a retracted position upon rotation of the striker support plate so that when the striker pin is engaged by the latch member bolt the striker support plate is rotated, the sliding door is moved between a partially open position away from the door opening in the vehicle body to a fully closed position in sealing engagement therewith. The later co-pending application in addition to disclosing the foregoing structure includes a crash worthiness feature therein that adds a pawl and ratchet mechanism to the striker support plate rotating means to prevent the rotating means from being reversely rotated in the event high door opening forces are applied to the door from the inside of the vehicle during an accident.
Although the final closing devices or clamping mechanisms of the aforesaid co-pending applications provide excellent final closing operations for sliding van doors, they do not include provisions therein for powering the sliding van doors through the major portions of their opening and closing movements, nor do they include provisions therein for powering the sliding van doors during the late closing movements thereof, to the point where the latch bolt mechanisms of the sliding van doors engage with and close about the striker pins of the clamping mechanisms.
It is, therefore, a primary object of the present invention to provide an improved powered sliding door operator and system for van type vehicles in which the sliding door is moved with low momentum from its fully open position to its nearly closed position, and vice versa, so as to reduce the safety hazards encountered in existing manual sliding doors and existing powered sliding door operators and systems.
Another object of the present invention is to provide a powered sliding door operating system for completely closing the sliding door in a slow controlled manner that obviates the safety hazard involved in rapidly closing or slamming sliding doors according to existing door designs.
It is yet another object of this invention to provide an improved powered sliding door operator and system in which the manual effort required to open and close the sliding door is substantially reduced or eliminated.
A still further object of this invention is to provide for near-normal manual operation of the sliding door in the event the powered sliding door operating system is not functional due to a vehicle accident, system failure, or the like.
An additional object of the present invention is to provide a powered sliding door operating system for van type vehicles which can be actuated either from the vehicle driver's seat or from the sliding door itself.
Further objects and advantages of this invention will become apparent as the following description proceeds.